Recurrence of Clostridium difficile-associated diarrhoea prevented by the administration of a whey concentrate from specifically immunised cows; prospective study

OBJECTIVE: To try to prevent recurrences of Clostridium difficile-associated diarrhoea (CDAD) by treatment with a specific neutralising secretory IgA-enriched whey-protein concentrate (40%) made from the milk of cows immunised with C. difficile and its toxins. DESIGN: Prospective, non-blinded, clinical cohort study. METHOD: In 2005-2006, 100 consecutive patients with CDAD received the whey concentrate for 2 weeks after completion of standard antibiotic therapy. For a period of 60 days after the start of the administration, the safety and preliminary efficacy of the whey concentrate were evaluated by means of a diary, blood determinations, active surveillance for adverse events, and the recurrence of CDAD. RESULTS: The whey concentrate was well tolerated and no safety issues were raised. Eleven out of 109 episodes (10%) were followed by a recurrence. After completion of the whey concentrate therapy, a positive test for faecal toxins or culture of C. difficile was predictive for the recurrence of CDAD (relative risk: 8.2 (95% CI: 1.04-64), and 4.7 (95% CI: 0.5-47), respectively). A positive faeces toxin during administration of the whey concentrate was also associated with an early recurrence of CDAD. CONCLUSION: Compared to historical and contemporary findings in control groups, the whey concentrate appeared to reduce the recurrence of CDAD by about 50%. However, the standard dose of the whey concentrate was probably not sufficient to fully neutralise the C. difficile toxins in faeces in all episodes.